BT told journalists yesterday it has 30,000 customers waiting for their Vision box to be installed by the end of the year, and that the target had always been 100,000.

We thought yesterday afternoon that maybe we didn't hear the BT Retail top brass right at the original Vision launch event - it happens. So we checked, and The Guardian agreed with our report, as did the analysts at Screen Digest (pdf).

Oh, and so did the BT press office. It said: "BT will start to fulfil orders from that customer base from mid December [2006], initially connecting thousands of customers then hundreds of thousands by the end of 2007. BT aims to have two to three million BT Vision customers in the medium term."

What a mystery. Enter a BT Retail spokesman, to clear up our confusion. He explained: "When we said the end of 2007, we of course meant the end of the financial year."

BT's financial year closes at the end of March. The spokesman said it is signing up 5,000 to 6,000 new vision customers per week.

Now, let's assume it meets 100,000 by the calendar year's end, and maintains that level of sign-ups in the new year. By our reckoning there'll be 13 weeks until March 31. 6,000 multiplied by 13 is 78,000. And 100,000 plus 78,000 is, erm, 178,000.

Correct us if we're wrong, but that's not "hundreds of thousands", is it? We are wrong, the spokesman said. "It is," he carefully explained.

With our dogmatic mathematical stance thoroughly debunked, we don't know which way is up anymore, so draw your own conclusions: is BT Vision on track? ®